Comment 1 for bug 570014

I've just fixed (or maybe just worked around, depending on how you see it) this issue by making btrfs compare the devno of the stat()'d file with the devno stat()'d from each mount point found in /proc/self/mountinfo. Attached is a patch, please do what you wish with it as you see fit. The patched ureadahead package can be found in my PPA (https://launchpad.net/~hyperair/+archive/ppa) for testing.